Within only hours of meeting unfamiliar peers, children with Attention-Deficit/Hyperactivity Disorder (ADHD) are typically disliked by the majority of the peer group. These findings are concerning because children with ADHD are already at high risk for developing depression, criminal behavior, substance abuse, and school failure in adolescence, and if they have peer relationship problems as well, the likelihood of poor outcomes multiplies. Developing effective interventions for the peer difficulties of children with ADHD has the potential to reduce their suffering and to diminish societal burden, carrying high public health significance relevant to the mission of NIMH. Unfortunately, existing medication, behavioral contingency management, and social skills training interventions have shown modest success to date on improving the peer acceptance and friendship of children with ADHD. In contrast to existing interventions that primarily focus on remediating deficits within children with ADHD that contribute to their social difficulties, this application assesses the feasibility of a novel intervention approach to increase the inclusiveness and the tolerance of the peer group that typically rejects the child with ADHD. I attempt to alter the stigma that a peer group may attach to ADHD symptoms and the negative cognitive biases the peer group may hold against a child with ADHD that perpetuates that child's negative reputation, even when the child with ADHD may display positive behavior change. Because elementary school-age children's social status is predominately determined by their classroom peers, this application tests the possibility that the teacher may be able to encourage a peer group that is more likely to be accepting of students with ADHD. I will develop the manualized treatment, appropriate procedures to assess fidelity of implementation, and pilot test an innovative approach to increase the inclusiveness and tolerance of the peer group in a controlled summer program setting. By attending to the understudied influence of the peer group on children's rejection and friendship, this research will ideally lead to the development of an improved treatment for social problems, and inform the submission of a follow-up study to assess intervention efficacy in community schools. PHS 398/2590 (Rev. 09/04, Reissued 4/2006) Page Continuation Format Page PUBLIC HEALTH RELEVANCE: Children with ADHD have severe problems getting along with peers, and these difficulties increase their risk for depression, delinquency, and school failure in adolescence. Peer relationship problems have proved refractory to existing treatments that focus on remediating deficits within the child with ADHD. This proposal tests a novel psychosocial treatment that trains elementary school teachers to increase the tolerance and acceptance of the peer group towards children with ADHD.